A robot-controlled microwave antenna system for uniform hyperthermia treatment of superficial tumours with arbitrary shape.
A system for microwave hyperthermia by scanning an antenna 'footprint' over a disease site is demonstrated. A computer-controlled robot arm scans a 2.45 GHz helical antenna and controls the absorbed power distribution. The 'ideal' power distribution required to achieve steady-state temperature uniformity over a given region has been calculated and a corresponding antenna trajectory programmed to approximate this pattern. Computer models, based on the solution of the bio-heat equation, have been implemented to allow various system parameters, such as antenna beam size, scan path and velocity profile, to be optimized. Experiments on a homogeneous muscle-equivalent phantom have shown that the scanning antenna system produces uniform temperature distributions over large areas of arbitrary shape. The addition of a thermal control system, based on temperature signal feedback, would enable 'real-time' modification of the power distribution and allow inhomogeneous and perfused tissue structures to be heated more uniformly.
Tennant
A
A
Department of Medical Physics and Clinical Engineering, Weston Park Hospital, Sheffield, UK.
Conway
J
J
Anderson
A P
AP
D003198:Computer Simulation; D004867:Equipment Design; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D008872:Microwaves / Q000627:therapeutic use*; D008953:Models, Anatomic; D009369:Neoplasms / Q000473:pathology / Q000628:therapy*; D013696:Temperature